Artificial arm



July 26, 1949. J. OTTERMAN 2,477,463

ARTIFICIAL ARM Filed Feb. 7, 1946 5 Sheets-Sheet 1 y 1949. J. OTTERMAN 2,477,463

ARTIFICIAL ARM Filed Feb. 7, 1946 s sh ets-sheet 2 MvenZor y v J. CSTTERMAN 2,477,463

ARTIFICIAL ARM Filed Feb. "I, 1946 5 Sheets-Sheet 3 6 wj/w wn July 26, 1949. J. OTTERMAN 2,477,453

ARTIFICIAL ARM 1 Filed Feb. '7, 1946 5 Sheets-Sheet 4 J. OTTERMAN July 26, 1949.

ARTIFICIAL ARM 5 Sheets-Sheet 5 Filed Feb. 7, 1946 122/6510 MZIM MAE/M I Patented July 26 1949 UNITE SIT actress ARTIFICIAL Joyce Otter-man,

Application Febrnary 7, 194(i Seria1 No,,63i6,133 In Great Britain septembergs, 1945 This invention relates toartificial arms, for use in cases ohamputation above the elbow, of the type comprising an elbow jointoperable by a fie iion. cord, wire or the like to flex the arm. Th fleXio-n cord, as is well known, is actuated by shoiildermo vement, chest movement or pedal movement of the person fitted with the arm.

It has beenproposed to fit such an arm with a hand, and to'u tilise thetrac-tion of the fiexion cord tofworki the hand, nsnallyby pulling a pivoted thumb toopenposition in relationto fixed fingers.

againstthe action eta spring. In the case of this b known construction, however, only that part of the" traction of the iiexion cord over and above thatre'quired'to flex the arm was availableito being utilised to flex the armor, where the elbow jointhas been loclgedjinladjustedpositicn, being expended in 'takin'g np lost motion. As the amolint offmove-ment which can be given to the fiexionvcord is atb est small, the hand cannot be satisfactorily operated in this way.

Thefinvention provides an artificial arm for use in "cases oi amputation above the elbow, and comprising an elbowjoint for enabling the. arm

to be flexed; a driving member for imparting movement to a hand or other appliance, an ope crating member actnable by a flexiblecord, and

a selector mechanismfor conplingthe operating member at will eitherto the elbow joint or to the drivingmember, andtherebypermitting of sepa.

rate and independent'oper aticn of the elbow joint and'of thedriving member under the control of the flexion cord."

By employing a selector, mechanism which can i couple the operating member jat will'either to the elbow joint orto thedriving member, the whole, of the pull'of thefleirion cord, is available for operating the selected= member, 1. .e. either for, 1

flexing the arm o'rfor working the hand or other appliance;

The arm fto the invention will normally comprise, af f oijearin nnit, to the wrist part of which'willbefittd the hand or other ap pliance, e. g. aspen 11- 01; or screwdriver, to which Y her will be coupled V 'Ihe hand or s preierablyldetachable from the i "m chan m-d ing Unite {States applicav-i V e dr i ns other'fapplian arm: and coupledfthereto by t. scribe .1

tiorfseri'alNd. 662,650, filed April 16, 1946, now

15 work the hand,. the major part of the traction 20 was (01. x ii mg usmbuaon which can be operated by the other han clion by press nreiof the arm against a table or other suriace, is provided for disabling the reversingmechanism; so enabling the driving member to be continuonslyjrotated in the same direction by repeatedtractionof the flexion cord. Thisis desirable whena screw driver appliance is In" 'a br'frred'ror inventi n comprises abnc i l V tand imat whme t to ted to rotate in relation to g the driving member, actuable by. a flexio n cord, ndas eeto iech, 'ingmember at will either to i th e tubelonto the gearing, traction, on theb flexion cord serving to ae itn 4 t cordingltoith etting dithe selector mechanism. 'otary driving member to a w e esllssfief ie ebemsmi approprieutilised for operating the hand or m according etc etc the accompany- Fig. 2 is a perspective view of the forearm erably ainaniialm operable means, e. g.-a project:

according to the a tube carrying the tovbe flexed, a rotary mi thetnbe, gearin snijfor coupling the operate tnbe er. the driving member acei u ll' qi-rihe t c d red; in detail, b

' operable by a snatch-pull cord I1.

supporting structure and part of the elbow mechanism,

Fig. 3 is a vertical section through the elbow mechanism drawn on an enlarged scale as compared with Figs. 1 and 2 and showing the parts in the position they occupy with the selector mechanism set for flexion of the arm and with the operating member in home position,

Fig. 4 is a section on the line IV-IV in Fig. 3,

Fig. 5 is a sectional plan View of the elbow mechanism, taken on the line VV in Fig. 3,

Fig. 6 is a section on the line VIVI in Fig. 5,

Fig. 7 is a section on the line VIIVII in Fig. 5,

Fig. 8 is a view similar to Fig. 6, but showing the parts in the position they occupy with the selector mechanism set for operation of the driving member and with the operating member moved somewhat away from home position,

Fig. 9 is a part sectional view showing an alternative form of latch for locking the forearm against rotary movement in relation to the upper arm, and I I Fig. 10 is a diagrammatic perspective-view of an alternative form of elbow mechanism which provides for pronation and supination of the hand as the arm is flexed.

Like reference characters denote like parts throughout the figure The arm (see Fig.1 comprises a bucket ll, of

leather, or other suitable material, to fit the stump,

and a forearmunit l2 enclosed in a plastic sheath l3. A flexion cord I4, which is attached to the wearers harnessin the usual way, serves either to flex the forearm, or to effect rotary movement of a drive shaft l5 according to the setting of a selector mechanism controlled by a selector lever I 6 As will be readily understoodthe cord 11 is worked by the chest muscles to operate the selector lever Hi, and

the flexion cord 14 is worked by the back muscles to perform the operation selected by the lever It.

The forearm carries a Wrist fitting l8 of the construction described incopending United States application Serial No. 662,650 aforesaid, to which an artificialhand or other appliance can readily be fitted as described in said application, rotary movement being imparted to the hand or appliance from the shaft I5 to operate the same by a barrel H9 in the wrist fitting, which engages a driving member in the hand or applianceas described, in the case of a hand, in United States application Serial N0. 644,498 aforesaid.

Theskeleton structure of the forearm unit l2, enclosed within the plastic casing I3, is shown in Fig. 2. It consists of fa pair of light metal side members united by cross bracings 2| and secured at their upperends by screws 22 to a cylinder 23 (see also Fig. 4) At their lower ends the members 20 aresecured to the wrist fitting is (not shown in Fig. 2) by screws passed through holes I24 in the members 20.

The cylinder 23 is rotatable in trunnion bearings 2 4 fixed to, and supported by webs 25 from, a ring fitting-26 carried by the bucket (see also Fig. 3). r The ring fitting 26 is outwardly flanged at its upper end and rotatable in relation to an inwardly flanged ring fitting 21 (Figs. 1 and 3) fixed to the lower end of the bucket I I. A plastic cap 28 is fixed to the lower end of the ring fitting 26 and serves as a housing for the elbow mechanism, being provided with a slot 29 (Fig. 1) through which the drive shaft [5 may pass.

It will be noted from Figs. 2 and 3 that the axis of the cylinder 23 is forwardly offset from the axis of the bucket and ring fitting 26, instead of in- *4 tersecting the axis of the bucket as is normal practice. This has the advantage that the fore arm can be flexed through a larger angle in relation to the upper arm. It also permits of shaping of the plastic cap 28 with a forwardly bulged portion as shown in Figs. 1 and 3-the plastic sheathing being cut-away as indicated at 3B in Fig. 1 to enable it to move over said forwardly bulged portion as the arm is flexed. This shaping of the cap 28 is of advantage as reducin the tendency of the wearers clothing to be caught between the forearm and upper arm, as compared with normal constructions in which the cap is hemispherical.

The flexion of the forearm is limited by a stud 3! (Fig. 2) on the cylinder 23 which projects upwardly into a slot 32 in the left hand trunnion 24, the ends of the slot 32 defining the limiting up and down position of the forearm in relation to th upper arm. The cylinder 23 is provided with a number of holes 33, two of which are seen in Fig. 2, which are engaged by a locking bolt 34 (Fig. 4) as later described to lock the forearm in adjusted position, a hole 35 being provided in the right hand trunnion 24 to allow the bolt 34 to move into locking position.

The forearm is rotatable about the axis of the upper arm by virtue of the rotatable mounting of the ring fitting 26 in the ring fitting 21, and is J normally locked in adjusted position by engagement of a ball 36, pressed by a spring 31, in one of a series of recesses 38 in the member 21 as shown in Fig. 3. If the wearer wishes to alter the setting of fitting 26, and therefore of the fore arm, in relation to fitting 21, he can do so by pushing on the forearm and moving it-round tothe desired position, whereupon the ball 36 will engage with another of the recesses 38 to relock the forearm. This rotational movement of the forearm is limited by upstanding studs 39 on the fitting '26 in cooperation with an inwardly projecting stud so on the fitting 2'! (see Fi s. 3 and 5).

Fig. 9 shows an alternative and more positive form of lock, which should preferably be used in conjunction with the ball lock shown in Fig. 3. This alternative lock comprises'a latch 4| pivoted at 42 to the fitting 2E and projecting through a slot 25 in fittin 26. This latch is spring'pressed by a, spring M4 into engagement with a selected one of a number of slots I45 in fitting 21, and requires downward pressure on its projecting end to release the fitting 26 for rotation in relation to the fitting 21. v

On the cylinder 23, and between the trunnions M, is rotatably mounted a pulley member, comprising a pair of spaced rings 44, 45 (Figs. 3-6) united by a bridge piece 46; The ring 44 is formed with a pulley groove 4'! (Fig. 4) r for the flexion cord and also with an outstanding grooved flange do to accommodate the tension spring 49. This, as shown most clearly in Fig. 6, is fixed at one end by a screw 50 to the pulley member, and at the other to an upstandin bracket 5| fixed to the ring fitting 26. The spring 49 normally retains the pulley member in the home position shown in Figs. 3-6, but traction on the flexion cord l iwill be effective to move the pulley member anticlockwise from this home position as seen in Fig. 6.

Rotary movement of the pulley member is effective, according to the setting of the selector lever it, either to flex the arm or to impart rotary movement to the drive shaft I5 to cause the same to operate the hand or other appliance fittedto the wrist mechanism 18., E'I he selector lever I6 (Fig. 5) is constituted by a cranked extension of eermce eleven tit-can be raised from thelowered positio v w et thoros t onehe n n: elt h lewi the lever-I16 is moved; down. age the sheet; 52 is rotated ot p -o eohwiee -u-., with the lower of thet '5 e e r rned ot oo eh eor anot er or y so e oth r odi i it n en the,1,BV l- -5 is e no eoe tioo,,r or tion of the pulley memher if t n m The m has 5. 12 z a pinfifl on the bolt 34;, and Q pos t on-of 19m s the arm ainelestheboit. te

, dies, Hate in Fi 4 o; remit he y inder Rio-roe ey n the t i ns1. -v 1h o he ooni on le v 53 car es ProJ Q io v v v too not m tot leroheo mom-b t. ft oerried hr l eyefif s idab y mount doo oi ed-Bit e o er; 6 is t p i io rthe erm-teho dst n. i in the tt m nd; o itionor l QdrQli as. s n n Fig. neo ioe he e ennoltmemoezell' is o t e p t nn F gs; i t maintained, with its net cord 1 er foreefieetrroto otthec li 23,;whlchis new: coupled-I tation: with the pundit mberr odre et e It wi eued r tooo; ot it w ,i -m is w t n held w eiti oienoith h 3 c n equent y n r i er with-newt" linthe home position of the pulleyemerrrher; Shouldcthe forearm be in en up pcsiti whenmhe; selector leverlfilsimoved uprt ret act the; hOlt3.4, the forearm willtend to; drop e to itsiwelght'auntil the l- 0 comes copes e e ho o teron Perm iofa ont oll dzflexion o the arm by theflexion 00mg When o yo n -l e movedz o heedown-t-posie tion; the sum 5A will move t t;,34 own-teem gage one ofH-the holes 33 in- -the cylinder 23,5;120J0fik the forearm, If the bolt 341g then npt immee dietely opposite a, holtv 33, the foreerrp fell htly byiv ravity toellowfih? bQltt {to engage-e h l a mo m iote r. Do nw rd-movement tl v r I ".li edi olooe-s.sl ev 5-to its up o t o o 5 as em oi ieefit hereb brin ing the W -P t Z-BMFie' jof; com slide to into onteet ith 't o ob tmeot-591 o-t eoaw1 w to. retract the letter from them-etch 13, The pu y me b is h w r o-torotetew, nthecylin-r der 23, lviovemeet of,.theilevee I6 to; the flown posi o al ende sv reret y tmeohaoism for o a i t eeh 12:15,.- whi mo henism-i end r ,in ect ve wheot ealoii r 6115 1 13 911 0? pin 67 on a calm slide fifi end ng the positign of c w-met heavywei ht.

A bevel wheel 2151 on tshaifit hi meshes. o pair of bevel wheels 19;;80 supportedbyzthe'snider 1-51 "and, carrying respectively ratchet wheels; 8 l, 82,-. A pair ofpawls, 843 184 are-pivotedonvthe in It carried by the pulley member andiareqconst aine y light springs 20.4 113:0 e ga e the ratchets. i} i 82: respective-1m Tanners; 85;. 85 on a shaft Slmounted forrctat-ion in thepullemmember, however, vcooperatt-ewithat'loe toilsrofitherpaawls e3, 84 to, ensurethot only ne. of: thewpawlszcan engage its ratchet atom-time; thestappetsrheing difierentlst ofiset inhalation. to the shaft: B1 [as shown.

When, the lever; I15 is 5111' the; up position tozsee lectrflexiorr ofv theerm; ,bot-hinewt/lle183r 84iereiheid inoperative, irrespective of the positionhofmthe Shaft y e followin mechanism. .Pivoted at88 (see'liig.,6)i toithe pullev memberrisi rocker frame 83 consisting QIJZWO sidernembersgalli-joined by a bridge-piece all. A rpin flz-joining thefiore ward ds f t de members: so eneaees'loeheath an extension: 93; ofvi-the couplingrpawl 111', ahdVw-hen the couplingpawle'miszin engagement with the recesgllinathe cylinder-23,thecrocker frame 89 is held zbythegspring 12;,inrthezpositi0n shown in Figs; 3landifi, inxwhiohifingerszaflliiomits ide members cooperate withthetailszofapewlsnsi 3 4 :tohold disengaged that-pne-aof thezpawlswhieh isnot so held-by itsitaphetyas shown in'fig. 6; :the spring I 2 .bei-ng strongerthan;the-pawlengaging spring 294.

When, however; the coupling pawl'llhie moved to disengagedposition: by downwardr movement of the lever Iii-,the rocket-frame:'fie isrmoved clockwise about its pivohBBrfitom theaposition'of Fig. 6 to that of Fig, 7, thus-lifting the-fingers 94 and allowingone or-the :paw-lsg 83;. 841 to engagev its ratchet. This; asSli-mingithetseleetor"lever I 6 to he moved down whenthepetilvis ttreiinzthepost tion shown :in Fig 6, would ibextherparwilfl 3: whose tappet 85 is in vhorizontaipositicn; 'I'hezothe'r pawl 84, despite :upwa-rdxmovementiofz thecoop crating finger 94, would; beth'zeldidisengeged' by its tappet 8o whichwis inuagsvertical position.

When the lever B: is inzdown positiomtherefore, traction on t cflexionicordrzwii l rotateone or. other -of,-the retchets and thuscause rotation of the driveshaft 11 tain. a direction determined by which Of the,;ratchets Ill, 82::is;coupled tot-lie pulley member byqits -associated ipawl.

Provision is made ;as:.=fol1ows 'for reversal of the pawl and ratchet engagement; andtherefore of the direction ofjrotationofishaft'fi; on succes sive ,-operations;ofrtherflexion icord." "I 'h'is is "re-e quired where opening: or cl-osing' of the hand is determined by the direction of rotation-off-shef-t lites described in United States application' 'serial N0; 69:4;498 aforesaid. Thessh'aft'il'l'carrying the tappetsxi85g 86 also carries a'star wheel ""96 coop; erating; with a-change-over-pawl 91 pressed to wardsiit' bye spring:98 (Fig; 31. on'return move ment otthe pulley member clockwise to home po sition underrthe infiuencemfPspring lqt the star wheel, 96cpushes the pawlfll' asidb At the loc ginnizigiofpthe next traction stroke,- however; the

ago-eras J to"turn'anti-clookwise,engage the'pawl 91 and be rotated by it through 90 to theposition' shown in Fig. 8, a spring-pressed ball 99, which projects between adjoining teeth'of the star wheel, being ipushed aside as the' star wheel turns, but spring ingforward again between the teeth to ensure true rotation through 90 of the star wheel. This 90' rotation reverses the p'osition'of the tappets,

as shown, and therefore the positionof thepawls,

:so that the required reversal of'thefdirection of rotation of shaft I5'is obtained. Y

Shortly before the'pulley member reaches home position on clockwise movement thereof by the spring it, a fixeci'ce'm 100 engages the rocker frame 89' to rock it clockwise intoposition to hold both'p'awls disengaged. This is to: prevent further rotation of shaft I5 in the previously'selected direction during the initial part of-the nextitraction stroke and before the'star wheel 95has been able to reverse'the;tappets. Immediately after the star wheel has performed its 90 rotation the rocker frame 89 clears the cam I and the spring I2 returns it to the position shown Fig. 8 in which the selected pawl is free to engage.

In some cases, aswhen the wearer is unable at one traction stroke to effect sufficient rota- ,tion" of'shaft I in the selected direction to open ,or close the hand, or desires to rotate a screw driver a number of times in the samedirection,

; jt. is desirable to disable the tappet reversing mechanisrn. This can be effected by rotation of ,1 a knob IOI (see Figs. 1 and 5) fixed to a spindle ,I02 having a cranked extension I03. When the ;knob is turned clockwise as seen in Fig. 3 from -;,thje position shown, the extension I03 'lifts the ,pa'wl '91 clear of the star wheel 96- and so dis- ;ables' the tappet reversing mechanism; until such time as the knob is restored to its original position,

Sometimes the wearer may be so injured that several part pulls on the flexion cord are needed fully to open or close the hand. In this case the traction on the cord will not be relieved suficiently at the end of each pull to allow the reversing gear to come into operation; and the ,efforts of the wearer are assisted by a relatively massive momentum wheel I04 (Fig. 2) near the avrist fitting, coupled to the shaft I5 by geari-ng I05. This will act as a flywheel and maintain the shaft I5 in rotation during the intervals between the pulls on the flexion cord, thus smoothing the movement of the hand from a series of jerks to a continuous movement.

In conclusion, it may in some cases be desired to effect pronation and supination of the hand as the arm is flexed, i. e. to cause the hand to ;;r.otate relatively to the wrist fitting, so as to approach the thumb towards the body, as the forearm commences to move up from its lower- ;most position and thereafter to rotate in the ::reverse direction relatively to'the wrist fitting ,as the forearm approaches the fully up position.

; Provision for this may bemade as shown diagrammatically in Fig. 10.

In this case theforearm carries .a rotatable sleeve I06 surrounding the shaft I5. Fixed to the ing the sleeve to rotate in the direction of the arrow A, as the forearm carriedby cylinder 23 swings upas shown Pyarrow B. in relation to 8 l the fixed pegs; As 'the forearm continues to move 'up,the gear III'I will come out of mesh with thepegs I09 and engage the pegs I08. Continued upward movement of the forearm will then cause reverse rotation of the sleeve I06 in relation to shaft I5 as shown by the arrow 0. h

;Rotary moveinent of sleeve I06 is arrangedto effect rotary movement of the hand in relation to thewrist' fitting as described in United States application "Serial No. 662,650 aforesaid.

"What I-clairna's my invention and desireto secure by Letters Patent is: u

'1. A'n artificial arm for use in cases of amputation above the elbow, and comprising a bucket for attachment to the stump, a forearmunit, a tubecarrying the forearm unit and mounted to rotate in relation to the bucket to enable the arm to'be flexed, a rotary driving member pro jecting from the tube and serving to impart operating movement to an appliance at the wrist of the forearm unit, gearing within the tube for rotating the driving member, a pulley mounted to rotate on the tube, a spring biasing the pulley to a home position, said pulley being rotatable from home position against said spring by traction on a flexion cord, and a selector mechanism for coupling the pulley at will either to the tube or to the gearing, whereby rotation of the pulley by the flexion cord will be efiective, according to the setting of the selector mechanism, to rotate said tube or to operate said gearing to rotate said driving member, said selector mechanism including a lever and a pawl controlled thereby for coupling the pulley, in one position of the lever, to the tube to cause rotation thereof with the pulley in the direction to raise the forearm unit. r

2. An artificial arm as claimed in claim 1, having a lock for locking the tube in various positions of adjustment thereof in relation to;the bucket and a connection between the lever and the lock for releasing the lock on movement of the lever into position to couple the pulley to the tube and for re-engaging the lock on movement of'the lever into position to couple the pulley to the rotary driving member.

3. In an artificial arm the combination of a tube supporting a forearm unit, hearings on an upper arm unit for supporting the tube, a rotary driving member extending forwardly from the tube along the forearm unit, gearing within the tube for rotating the driving member, said gearing comprising a pair of gear wheels, which are alternatively operable on the driving member to drive it in opposite directions, a pair of ratchets one for driving each gear wheel, an operating member actuable by a flexion cord and rotatably mounted on the tube, a spring for biasing the operating'member to a home position, a pair of pawls carried by said operating member and one associated with each of the ratchets, a shaft rotatably mounted on the operating member, a pair of tappets carried by the shaft and serving to maintain one or other of the pawls disengaged from its ratchet according to the position of the shaft, a star wheel on the shaft, and a changeover pawl arranged to cooperate with the star wheel to -reve'rse-the position of the tappets and therefore the engagement of the pawls at each operation of the flexion cord.

'4. Apparatus as claimedin claim 3, in which the change-over pawl is effective to rotate the star wheel as the operating member commences to move from its home position, and comprising a fixed camoperative to maintain both pawls 9t disengaged from their ratchets when the operating member is in thehonie position and until it has moved therefrom suificifently for the star wheel to operate;

5. Apparatus asclaimed in claim 3, comprising a selectormembermovable: from a first to a second position; a lock for locking the tube against rotation in relation to its bearings, means for retaining the lock inlocking position when the selectormember is in its first position and for retracting the look from locking position when the selector member is in its second position, a driving pawl controlled by th'eselector member andoperable to couple the operating" member to thetube-to effect rotation thereof only when the selector member is in its second position, and means operated by" theselector member when in its second position foriholding both. of the ratchet engaging pawl's disengaged from their ratchets.

6. Apparatus as claimed in claim 3, comprising a selector member movable from a first to a second position, a lock for locking, the tube against rotation in relation to its bearings, means for retaining the lock in looking position when the selector member is in its first position and for retracting the look from looking position when the. selector member in its second position, a driving pawl' controlled by the selector member and operable to couple the operating member to the tube to effect rotation thereof only when the selector" member is in its second position, and a rocking frame mounted on the operatingmember and cooperating with the ratchet engaging pawlsand? with the: driving pawl, said the driving; pawl. is moved out ofoperative position;

7. Apparatus asiclaimed in claim 3', comprising, a selector membermovable from a first to a second position, a loclc for locking the tube against rotationinrelation to its bearings, means for retaining the lock in looking position when theselector member is in its-(first position and for retracting the; look from. looking position when the selector member." is in its second position, a driving pawl controlled. by the selector member and operable to couple the: operating: member to the tube toefiect' rotationthereof only when the selector member is. in its secondiposition, a rocking frame mounted on. the: operating member and cooperating withthe: ratchetengaging pawls and with the. driving pawl; said: rocking frame maintaining both ratchet engaging pawls. disengaged when the driving pawl is: in. operative position but freeing the ratchet: engaging pawls for engagement with their: ratchetsi whenthe driving pawl is moved out of operative position, and a fixed cam for cooperating with-the rocking frame to cause it tomaintaln the-ratchet engaging pawls disengaged when the; operating member is in the home position. a

8. In an artificial, arm the combination of a tube supporting aiorearnr unit, bearings on the upper arm unit for. supporting the; tube, a rotary driving, member extendingiorwardl'y from the tube along: the. ioreamn unit, said driving member serving, when rotated, to impart operating movement. to: an; artificial' hand, gearingwithin the tube for rotating the driving member, means for turning the tube in its bearings to flex the arm, a. sleeve. surrounding the driven member l0 and rotatably supported bythe forearm unit, a mutilated gear on said sleeve, and pegs on the bearings which serve to engage the gear, as thearm is flexed, to effect rotation of the tube first in one direction and then in the reverse direction and thereby to impart movements of pronation and supination to the hand.

9. An artificial arm for use in cases of amputation above the elbow and comprising a bucket for attachment to the stump, a; forearm unit, a tube carrying the forearm unit and mounted to rotate in relationto the bucket to enable the arm to be flexed, a rotary driving member projecting from the tube, gearing within the tube for rotating the driving member, said gearing comprising a pair of gear wheels which are alternatively operable on the driving" member to drive it in opposite directions, a rotary operating member actuable by a flexion cord, a selector mechanism for coupling the operating member at will either to the tube or to the gearing to enable traction onthe flexion cord to rotate either the tube alone or the driving member alone according to the setting of theselector mechanism, a ratchet associated with each gear Wheel, a pair of pawlscarried by the operating member, one for cooperation with each ratchet, mechanism operable by the selector mechanism for moving the pawls into and out of operative relationship with the ratchets, means connecting the pawls for maintaining one of thepawls disengaged from its ratchet when the other is engaged, and a reversing mechanism which oncrates automatically to reverse the pawls and therefore the direction of rotation of the driving member between consecutive operations thereof.

10. An artificial arm for use in cases of amputation above the elbow; comprising a bucket; for attachment to the stump, a forearm unit, a cylinder fixed to the upper end of the forearm unit, bearings carried by the bucket for supporting the cylinder, a ring fitting for supporting the bearings, a cooperating ring fitting on. the bucket in relation to which the first-mentioned ring fitting is mounted for rotation-and means for latching the two ring fittings together in one of a plurality of positions of'relative. adjustment.

11. An artificial arm for use in cases of. mp tation above theelbow, comprising a bucket for. attachment to the stump, a. forearm unit, a cylinder fixed to the upper end 01! the forearm unit, bearings carried by the bucket for supporting the cylinder, at wrist fitting, at the. endof the forearm unit, means operable by a flexion cord for rotating the cylinder. in. its hearings. to flex the arm, a rotary driving. member projecting fromthe cylinder, meanslikewise operable. by the flexion cord for rotating the. driving. member, a driven member in the wrist; fitting, a drive shaft coupling the driving... member and the driven member, said drive shaft having flattened ends engaging within hollow endslof said driving and driven members, a pair. of transverse pins located in the hollow portion of the driving member and arr-1,463

11 actuable by a flexion cord, a first one way driving connection forimparting movement from said operating member to'said elbow joint, a second oneway drivingconneotion for impartingmovement from said operating member to said driving member, and a selectormechanism interlinking said one way driving connections so that but one of them at; a time is effective, said selector mechanism being movable at will to alternative positions, in one of which the first one way driving connection is effective to enable traction on the flexioncord to operate the elbow joint and flex the arm and in the other of which the second one way driving connection is effective to enable traction on the flexion cord to rotate the driving member. 1 i I r 13. An artificial arm, for use in cases of amputation above the elbow, and comprising an elbow joint for enabling the arm to be flexed, a rotary driving member for imparting movement to a hand or other appliance, an operating member actuable in forward: direction from a neutral position by 'afiexion cord a spring for returning the operating member toneutral position on release of tension in-the flexion cord, a first one Way driving connection for transmitting forward movementfromthe operatingmember to the elbow jointrasecond-one way driving connection for imparting, on forward movement of the op erating member, movement in either of two directions to the rotary driving member, a selector mechanism interlinking; said one way driving connections so that 'but-onepfthem at a time is effective, and, a reversing mechanism, operative only when the selector mechanism is positioned to renderlsaid second one way driving connection eifective for automatically reversing the direction of the rotation. imparted to the driving member by successive forward movements of the operating member.-

14. An artificial arm asclaimed in claim 13, comprising manually operable means for rendering the reversing mechanism ineffective.

15. An artificial armfor use in cases of amputation above the elbow and comprising a bucket for attachment to the stump a forearm unit, a tube' carrying the lforearm unit and mounted to rotate in relation to .the bucket to enable the arm to be flexed, arotary driving. member projecting from the tube, gearing within the tube for rotating the driving member, an operating member actuable in'forward direction from a neutral position by afle'xion cord, a spring for returning the operating member. to neutral positionon release of tension in the flexion cord, a first one way driving connection for transmitting forward movement from the operating member to the tube, to enable the tube tobe rotatedby a pull on the flexion cord to flex the arm, a second one way driving connection for transmitting forward movement from the operating member to the gearing to enable the gearing-to be operated by a pull on the flexion cord torotate the driving member, and a selector mechanism interlinking said one way driving connections so that but one of them at a time is effective. V

16. In an artificial arm, the combination of a tube supporting a forearm unit, bearings on an upper arm unit for supporting thetube, a rotary driving member extending forwardly from the tube along the forearm unit, forward and. reverse gearing within the tube for rotating the driving member, an operating member operable in one direction by traction on a fiexion cord to drive the gearing and therefore the driving member, a

driving member extending forwardly from the tube alon the forearm unit, a pair of ratchet wheels geared to the driving member and operable to rotate the driving member in opposite,

directions, an operating member rotatable in one directionbytraction on a flexion cord, a spring for imparting return movement to the operating member on release of tension in the flexion cord, a pair of pawls carried by the operating member, each pawl being associated with one of the ratchets and being operative to turn its ratchet when the operating member is rotated by the flexion cord, and a manually operable member coacting withsaid pawls and movable into alternative positions-toefiect alternative disengagement of said pawls from their respective ratchets.

18. In an artificial arm, the combination of a tube supporting aforearm unit; bearings on an upper arm unitfor supportingthe tube, an operating member rotatable in one direction by traction on a flexion, cord, 3, spring for impart,- ing return movement to the operating member on release of tension in the flexion cord,,and a pawl on the operating member for engaging a notch in said tube, said pawlbeingeffective, on rotation of said operatingmember in response to traction on the fiexion cord, to rotate the tube and therefore to flex the arm. 1 V

19. An artificalarm for. use in casesof amputation above the elbow, and comprising an elbow joint for enabling the arm to be flexed, a rotary driving member for imparting movement to a hand or other appliance, an operating member actuable by a fiexion cord, a selector mechanism for coupling the operating. member atwill either to the elbow joint or' to theidriving member, and thereby permitting ofseparate and independent operation, according to the position of the selector mechanism, either of the elbow joint or of the driving member under the control of the flexion cord, a locking member for locking the elbow joint to prevent flexing of the arm,

and means linking the selector mechanism to the locking member and serving to render the locking member ineffective, on movement of the selector mechanism into position to couple the operating member to the elbow joint and to restore the locking member to effective position on movement of the selector mechanism into position to couple the operating member to the driving member. 1

20. An artificial arm for use in cases of amputation above the elbow, and comprising an elbow joint for enabling the arm to be flexed, a driving member for imparting movement to a hand or other appliance, an operating member actuable by a flexion cord, a first driving connection for imparting movement from the operating member to the elbow joint, asecond driving connection for imparting movement from the operating member to the driving member, and a selector mechanism interlinking said driving connections so that but one of them at a time is effective, said selector mechanism being movable at will between alternativepositions, in

one of which the first driving connection is effective and in the other of which the second drivin connection is effective.

JOYCE OTTERMAN.

REFERENCES CITED The following referenkzes are of record in the file of this patent:

UNITED STATES PATENTS Name Date Beacock et a1 Nov. 10, 1885 Number FOREIGN PATENTS Number Country Date 115,753 Great Britain May 23, 1918 133,344 Great Britain Oct. 16, 1919 OTHER REFERENCES Report of European Observations, by Commission on Amputations and Prostheses, received in Div. 55 of the U. S. Patent Oflice Feb. 12, 1947, pp. 22 and 28. 

